1. Field of the Invention
The present invention relates to novel organic compounds, to methods for their preparation, to compositions containing them, to their use for treatment of human and animal disorders, to their use for purification of proteins or glycoproteins, and to their use in diagnosis. The invention relates to modulation of the activity of molecules with phospho-tyrosine recognition units, including protein tyrosine phosphatases (PTPases) and proteins with Src-homology-2 domains, in in vitro systems, micro-organisms, eukaryotic cells, whole animals and human beings.
2. Background of the Invention
Phosphorylation of proteins is a fundamental mechanism for regulation of many cellular processes. Although protein phosphorylation at serine and threonine residues is quantitatively dominating in eukaryotic cells, reversible tyrosine phosphorylation seems to play a pivotal role in regulation of cell growth and differentiation as well as in neoplastic transformation (Hunter, Cell 80: 225-236 (1995); Schlessinger and Ullrich, Neuron 9: 383-391 (1992); Cantley et al., Cell 64: 281-302 (1991); Ullrich and Schlessinger, Cell 61 :203-212 (1990); Hunter, Curr. Opin. Cell. Biol. 1: 1168-1181 (1989)); Hunter and Cooper, Annu. Rev. Biochem. 54: 897-930 (1985)).
The regulation of protein tyrosine phosphorylation in vivo is mediated by the opposing actions of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPases). The level of protein tyrosine phosphorylation of cellular proteins is determined by the balanced activities of PTKs and PTPase (Hunter, 1995, supra).